Hydrofluorocarbons (i.e., compounds containing only the elements carbon, fluorine, and hydrogen) and hydrohalofluorocarbons (i.e., compounds containing only the elements carbon, fluorine, hydrogen and chlorine and/or bromine) are widely used as refrigerants, aerosol propellants, blowing agents, cleaning agents, fire extinguishants and chemical intermediates. Commercially, many of such compounds are prepared by the reactions of hydrogen fluoride with olefins or saturated compounds containing chlorine. Some compounds (e.g., various hydrofluorocarbons) can be prepared by the hydrogenolysis of an appropriate chlorine and/or bromine-containing precursor. These processes can also produce halogenated hydrocarbons having a lesser commercial value and/or not having the desired properties. Furthermore, the supply/demand situation for any particular product can vary and there may be an oversupply of a particular hydrofluorocarbon or hydrohalofluorocarbon. For environmental reasons, it may not be advantageous to dispose of surplus or by-products by such methods as incineration, but rather to further react these materials to increase the yields of useful products. A reduction of the fluorine content of various hydrofluorocarbons and hydrochlorofluorocarbons can improve their value as commercial products and/or as precursors for producing other useful products.